At least 12 people have suffered burns from a suspected “noxious substance” at a club in east London, police say.
Hundreds of revellers were evacuated from Mangle E8 in Sidworth Street, London Fields, after police were called at about 01:10 BST.
Police said 10 of those affected were taken to hospital by ambulance, while a further two presented themselves at A&E.
Their injuries are non life-threatening.
It is understood about 600 people had been attending an event at the nightclub before it was evacuated.
A Scotland Yard spokesman said the 10 people were treated for minor burns at the scene before being taken to hospital.
No arrests have been made and officers are continuing to investigate, he added.
Witness Phie McKenzie tweeted: “Scary scenes tonight, we have heard reports of chemical burns of people in the building here”.
London Ambulance Service said it sent a number of ambulance crews and a hazardous area response team to the venue.
